Putting a price on road space seems like a good idea but some analysts argue it could actually increase the amount of driving. In fact there's a point of view that says it would be better to promote traffic congestion.

I’m not aware of anyone who disagrees seriously with the contention that car travel is underpriced. The consequence of this inefficiency is we drive more than we otherwise would and more than is socially optimal. The idea of road pricing is that drivers should pay the real costs they impose on others through traffic congestion, […]